Fatty Liver Disease Tied to Diabetes, Atherosclerosis

Non-alcoholic fatty liver disease (NAFLD) is an independent predictor of both type 2 diabetes and carotid atherosclerosis, according to two studies…. 

In a retrospective study conducted in Japan, people with NAFLD had nearly three times the risk of developing diabetes than people without the condition. Moreover, improvements in NAFLD reduced the risk of incident diabetes over about an 11-year follow-up.

Researchers looked at records for 8,070 patients who had voluntary checkups at least a decade apart and who had an abdominal ultrasound at each visit.

Hajime Yamazaki, MD, of Teine Keijinkai Hospital in Sapporo noted that patients were excluded if they had hepatitis B or C, drank more than 20 g of alcohol a day, or had diabetes at the first visit. After the exclusions, the researchers were left with 3,074 participants, who were divided into 728 with NAFLD and 2,346 without NAFLD, based on their ultrasound results.

The group with NAFLD at baseline was then divided again into those who still had the condition at the second visit and those who no longer had it — the "improved" subgroup.

Overall, incidence of type 2 diabetes was 6.1% over the follow-up, Yamazaki said, but was much higher among those with NAFLD at baseline — 16.1% versus 3.1% among those without fatty liver.

After adjustment for age, sex, body mass index, family history, dyslipidemia, and hypertension, Yamazaki reported, those figures yielded an odds ratio for diabetes of 2.82 (95% CI 1.91-4.15, P<0.001). Moreover, he reported, the 100 patients whose NAFLD improved over the 10 years had a much lower incidence of diabetes than the 618 who continued to have the condition — 6.4% versus 17.8%. The figures yielded an adjusted odds ratio for diabetes of 0.30 in favor of the improved group (95% CI 0.13-0.66, P=0.003).

During the same session at the annual meeting of the European Association for the Study of the Liver, Raluca Pais, MD, of Pitié-Salpêtrière Hospital in Paris, and colleagues reported that NAFLD is an independent predictor of carotid atherosclerosis.

Pais noted that previous research has shown that patients with NAFLD have an increased prevalence of cardiovascular disease and that they tend to develop carotid atherosclerosis earlier than their healthy counterparts. But it’s not clear whether the fatty liver is an independent risk factor or has its effects through the underlying metabolic disorder.

Pais and colleagues studied the records of patients at high risk for cardiovascular events. They began with a cross-sectional snapshot of 5,671 patients with at least two cardiovascular risk factors and ultrasound measurements of carotid intima media thickness (C-IMT) carotid plaques. NAFLD was defined as a fatty liver index of 60 or greater, and the researchers used the gender-specific Framingham score sheet. A subset of the participants was then followed for an average of 8 years.

The snapshot analysis showed that 33% of the patients had NAFLD, the average C-IMT was 0.63 millimeters, 39% had carotid plaques, and the average Framingham score was 10.

But all of the risk factors for cardiovascular disease were significantly more prominent among the 1,871 patients with NAFLD, including body mass index, waist circumference, diabetes, hypertension, smoking, and alcohol consumption. In particular, the NAFLD participants had a greater C-IMT (0.64 millimeters versus 0.61), more plaque (44% versus 37%), and a higher Framingham score (15 versus eight).

Over the follow-up period, C-IMT, carotid plaque percentage, and the proportion of patients with NAFLD all rose, as did average body mass index, waist circumference, and use of lipid-lowering drugs.

But only three baseline factors predicted carotid atherosclerosis — age, tobacco use, and NAFLD, she said.

• People with NAFLD had nearly three times the risk of developing diabetes than people without the condition.
• Three baseline factors predicted carotid atherosclerosis — age, tobacco use, and NAFLD
• Note that these studies were published as abstracts and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.

Presented at the annual meeting of the European Association for the Study of the Liver, April 1, 2014